This invention relates to footwear and more particularly to heel inserts which deform temporarily under heel-strike acting as a shock absorber and torque controller to aid in the prevention of ankle, knee, leg and tendon injuries during various physical activities.
Each foot contains, besides the bone structure, 19 muscles plus the tendons of 12 more muscles situated in the leg, more than a hundred ligaments, tough connective and protective layers of fascia and toe nails. It also contains yards of blood vessels and intricate networks of nerves.
A foot in action goes through three forward motions, namely heel impact, a transitional horizontal balance phase, and the thrust of the toes, to move the individual into a repetition by the opposite foot of the exhilarating rhythm the comprises walking.
Running and jogging intensifies that shock pressure and/or stress on the feet and particularly the heel since it is the heel, as noted from above, that first receives the weight of the body, i.e. heelstrike. Walking, running and exercising on a hard or inflexible surface aggravates foot problems since by nature the foot is intended to flex on impact with the ground. Thus, a new heel shock absorber is needed to reduce the harmful effects of the impact or heelstrike which transmits stress and bio-mechanical twisting to the foot, leg and the back muscles.